DBManager: don't raise any errors while disconnecting signals from de…

…stroyed objects

python/plugins/db_manager/table_viewer.py

@@ -67,7 +67,12 @@ def setDirty(self, val=True):
 
 	def _clear(self):
 		if self.item is not None:
-			self.disconnect(self.item, SIGNAL('aboutToChange'), self.setDirty)
+			try:
+				self.disconnect(self.item, SIGNAL('aboutToChange'), self.setDirty)
+			except:
+				# do not raise any error if self.item was deleted
+				pass
+
 		self.item = None
 		self.dirty = False
 
@@ -83,11 +88,13 @@ def _loadTableData(self, table):
 			self.setModel( table.tableDataModel(self) )
 
 		except DbError, e:
-			QApplication.restoreOverrideCursor()
 			DlgDbError.showError(e, self)
+			return
 
 		else:
 			self.update()
+
+		finally:
 			QApplication.restoreOverrideCursor()